Hadron structure and interaction from lattice quantum chromodynamics calculations

The authors report the results of the U.S. Department of Energy Grand Challenge project on the ab initio calculations of hadron structure (proton, neutron, and other strongly interacting particles) and interaction in the framework of lattice gauge quantum chromodynamics. The electric and magnetic form factors which are deducted from the elastic scattering of electrons off the proton and neutron targets are simulated on a quenched 163 x 24 lattice. The masses of the exotic four-quark mesoniums, the molecules of the strongly interacting mesons, are calculated on a 24 x 12 x 12 x 24 lattice. Stable and metastable configurations are found in certain quantum states. This finding agrees with the observed experimental trend